WTF Fuel cut or detonation?

[14LBS]

I know that i have asked this b4, but i am boosting 81/2- 9lbs spiking to 91/2-10lbs and it doesnt do it all the time but it's the same jolt when you hit your governer kind like hesitates till you let off the gas. any clus or has any1 had a similar experience. :mad:

[DiscreetSpeed]

fuel cut my friend, i know it sucks.

[14LBS]

so what will happen if i dont let of the gas? will it jess keep cutting in and out?

[14LBS]

i see your boosting 12 daily what mods do you have and do you hit this fuel cut?

[unwrittenLaw]

I think its a spark cut and its based on airflow, not actual PSI. So depending on weather,etc...you might be able to boost to 12 on warmer days w/o hitting it and less on cooler days...

[14LBS]

spark cut???

[14LBS]

how do i fix this spark cut?

[unwrittenLaw]

You'd have to get a standalone to control timing, etc..
The fuel/spark cut is actually a good thing because it prevents you from destroying your engine...

[14LBS]

thats what i hear. hey your in san diego also???

[unwrittenLaw]

yup

[14LBS]

coo same here.

[unwrittenLaw]

cool

[ATLskate]

Originally posted by perfworks
Well as the title reads we have learned that there isnt a programmed fuel cut in the MSP. The problem arises when the MAF meter is "maxed" out. It is a 0-5 volt meter. Some will experience a cut in fuel because the meter has read enough airflow to exceed the 5.0 volt limit. ALL THE PROTEGES have this . Not just the MSP.
Now depending on many factors the "fuel cut" will happen at different psi ranges for everyone. The denser the aircharge thru the meter (and what the temp sensor reads ) the quicker it will bottom out the meter. Also there have been cases with short ram intakes causing problems, by "washing" the filter with the radiator fan. It will cause an increase in airflow turbulence in the meter and throw off the readings. Either causing harm or good depending on the rpm and ambient temp. Also many meters have different starting ranges that are within factory spec. Some meters will run at idle 1.6 volts while some others run 2.2 volts. That .6 volt can mean the difference between running 8psi and running 10psi of boost.
Well just wanted to shed some light on a subject that has been overblown. There is no fuel or boost cut. It is just that the meter has reached its efficiency limit and the ecu doesnt want more that that much airflow thru the system. Your stock turbo was sized using all the stock sensor outputs. Since it was used in N/A vehicles then it was a safety devise because it would only compensate for about 20% more airflow. This is all that the engineers intended. I wish mazda wasn't in such a rush to bring this vehicle out and put some more thought into it. Well at least they gave you guys a great car to base some mods in with the LSD and larger axles. All you need is a larger exhaust & downpipe, FMIC and a piggyback (hint hint:D ) and you could get some great numbers from that little turbo.

[14LBS]

so your sayin that this wont blow my motor or anything.

[ATLskate]

no, it probally won't. Basically the ECU freaks out once the 5V max has been reached, so it cuts the fuel delivery for a few cycles.

[Notorious]

If you all are from san diego....


COME OUT TO THE MEETS!

[KzA]

the best way to get around it is to get the 80mm mass air from MPI and tune it with the piggyback..it will alleviate your probelsma nd allow you to run more, safer boost

[DiscreetSpeed]

^^^ooh id want that but would i really need a piggy back for it to work properly work?

[14LBS]

whats the 80mm mass air and whos mpi

[KzA]

Modern Performance Inc..the 80mm mass air allows much more airflow over the stock one., and yes you need the piggyback in order to tune the massair(since the stock ecu will have no idea whats going on when you put on the new mass air..)

[unwrittenLaw]

Originally posted by Notorious
If you all are from san diego....


COME OUT TO THE MEETS!


I'm from San Diego, but I don't live there at the moment....I'm moving back down there in a month...then I will be at the meets...

[hukster00]

isent the meeter 5-10v ? thats y the afc wont work on our cars :( cuz it only reads 0-5 ?

[KzA]

I would trust what perfworks says.,..hes dont ALOT to these cars and knows his shit..I know first hand...

[chinkysuavo]

Originally posted by Notorious
If you all are from san diego....


COME OUT TO THE MEETS!
(lol) way to do ur job Peter! Yea, I have the exact problem, when I dyno'd the car I was able to boost 12 with no fuel cut, now that its gettin cooler, I'm limited to 10 unless I like that running into a brick wall feeling. I have been considering the Joe p. Fuel Cut Defenser but it definetly increases the risk of detonation.

[Striker187]

Originally posted by hukster00
isent the meeter 5-10v ? thats y the afc wont work on our cars :( cuz it only reads 0-5 ?

correct.

also, it IS spark cut rather than fuel cut right? cause you certainly don't want a super lean mixture which will lead to detonation right?

[Flat Black]

You want a cheap fix to boost a little more than you should. REMOVE THE FUCKING AIR TEMP SENSOR IN THE INTAKE BOX.

[chinkysuavo]

Originally posted by Flat Black
You want a cheap fix to boost a little more than you should. REMOVE THE FUCKING AIR TEMP SENSOR IN THE INTAKE BOX.

remove it? just disconnect it and leave it hangin there or unplug the sensor from the harness?

[perfworks]

Originally posted by Striker187
correct.

also, it IS spark cut rather than fuel cut right? cause you certainly don't want a super lean mixture which will lead to detonation right?
it is a 0-5 volt meter.
there is no spark cut. it is all fuel thru the MAF. the ecu shuts down the injectors.

[Flat Black]

Originally posted by chinkysuavo
remove it? just disconnect it and leave it hangin there or unplug the sensor from the harness?

You can just disconnect it man. No joke.

[chinkysuavo]

so how much more can u boost after removing it...i'm assuming i'd have to plug the hole on the intake...will the throw a CEL?

[Flat Black]

Originally posted by chinkysuavo
so how much more can u boost after removing it...i'm assuming i'd have to plug the hole on the intake...will the throw a CEL?
1-2 pounds. You don't have to plug the hole, I've been driving like 1300 miles like that. Yes, it will throw a CEL. Kind of annoying.

[chinkysuavo]

koo, thanks. maybe i'll try it at the track

[NeverSober]

Mine is removed to, the check engine light was on until I put the temp sensor back on and just zipped tied it to the coldest part of my engine(away from heat). If you don't have the sensor still ont he battery light and check engine light will come on. The reason mine is removed is because I have the Spool CAI. No place for the sensor.


Chris

[speed1]

This all seems to make sense and be helpful for someone who has opened the waste gate on their car and is now running more boost, but what about someone like me who hasn't touched it due to lack of aftermarkets. This may have been discussed already in an earlier thread but I've been gone a while.
My car is perfectly stock right now (MSP stock). But my acceleration is eratic, idle sometimes bogs down and boost sometimes even seems to reduce power. It is almost as if there isn't enough fuel getting to the cylinder. My dealership said that someone is working on a new program but I don't beleive it. Has anyone else had this problem? And If this is the wrong area to ask this question, help me get it to the proper area.

[Dexter]

Originally posted by speed1
My dealership said that someone is working on a new program but I don't beleive it.


http://www.msprotege.com/vbb225/showthread.php?s=&threadid=30901

[DiscreetSpeed]

right on dex...^^^